PORTLAND, Maine (AP) – A Massachusetts man was sentenced to six months in jail Tuesday for violating a federal law that makes it illegal to buy and sell fish that have been forbidden in certain bodies of water in Maine.

Michael Zombik pleaded guilty to one count of knowingly selling live shiners, a type of bait fish, to a man from Cornish and to an undercover agent posing as a buyer from Maine. Maine law prohibits importing bait fish.

The federal law, known as the Lacey Act, makes it a crime to engage in the interstate commerce of fish that has been caught, transported or sold in violation of state law.

Zombik, who was sentenced in U.S. District Court, also pleaded guilty to knowingly selling largemouth bass to a Cumberland man to stock a private pond and buying live game fish from an undercover agent posing as a Maine seller.

It is illegal in Maine to purchase or sell live largemouth bass that have not been legally imported. The laws are designed to protect sensitive ecosystems that would be threatened by foreign fish species, officials said.

The sentencing marks the end of an investigation that began in 2000 and involved the Maine Warden Service, U.S. Fish and Wildlife Service, Massachusetts Environmental Police and the New York Department of Environmental Conservation.